The method is far more complicated than i thought and it uses various things that i never heard previously (such as Feldman’s verifiable protocol). Additionally there are many things that i couldn't understand such as
1.They convert the(2, 3)-threshold shares xi of x into(2, 2)-threshold shares wi of x with appropriate Lagrangian coefficients
I don't say it's bad method (rather i find it interesting), but it's very complex while involving third party (Service Provider and Recovery Server in this case).It's definitely not for people like me.
This method an evolution of the one that is currently used by Conio to provide a safe clients’ bitcoin custody at Hype.
The setup is meant to provide the user the full control of his bitcoin without the hassle and the responsibility of custody of his private key. We know that users are seldom their own worst enemy, not backing up her private key, losing access to their devices or generally doing stupid things.
So this setup is meant to “protect” the waekest link in the user/custody/service provider, letting him in control of his private key, but being able to recover access to funds in case of a major disaster.
In the coming months, I’ve been told Conio will release a wallet under this scheme, and next they will implement in their Hype solution.